scholarly journals Manganiakasakaite-(La) and Ferriakasakaite-(Ce), Two New Epidote Supergroup Minerals from Piedmont, Italy

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 353
Author(s):  
Cristian Biagioni ◽  
Paola Bonazzi ◽  
Marco Pasero ◽  
Federica Zaccarini ◽  
Corrado Balestra ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Empirical Formula ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Ore Deposit ◽  
Cell Parameters ◽  
Homogeneous Domains ◽  
Mn Ore

Two new monoclinic (P21/m) epidote supergroup minerals manganiakasakaite-(La) and ferriakasakaite-(Ce) were found in the small Mn ore deposit of Monte Maniglia, Bellino, Varaita Valley, Cuneo Province, Piedmont, Italy. Manganiakasakaite-(La) occurs as subhedral grains embedded in pyroxmangite. Its empirical formula is A(1)(Ca0.62Mn2+0.38) A(2)(La0.52Nd0.08Pr0.07Ce0.07Y0.01Ca0.25) M(1)(Mn3+0.52Fe3+0.28Al0.18V3+0.01) M(2)Al1.00 M(3)(Mn2+0.60Mn3+0.27Mg0.13) T(1−3)(Si2.99Al0.01) O12 (OH), corresponding to the end-member formula CaLaMn3+AlMn2+(Si2O7)(SiO4)O(OH). Unit-cell parameters are a = 8.9057(10), b = 5.7294(6), c = 10.1134(11) Å, β = 113.713(5)°, V = 472.46(9) Å3, Z = 2. The crystal structure of manganiakasakaite-(La) was refined to a final R1 = 0.0262 for 2119 reflections with Fo > 4σ(Fo) and 125 refined parameters. Ferriakasakaite-(Ce) occurs as small homogeneous domains within strongly inhomogeneous prismatic crystals, where other epidote supergroup minerals coexist [manganiandrosite-(Ce), “androsite-(Ce)”, and epidote]. Associated minerals are calcite and hematite. Its empirical formula is A(1)(Ca0.64Mn2+0.36) A(2)(Ce0.37La0.17Nd0.06Pr0.03Ca0.35□0.02) M(1)(Fe3+0.61Al0.39) M(2)Al1.00 M(3)(Mn2+0.64Mn3+0.33Fe3+0.02Mg0.01) T(1−3)Si3.01 O12 (OH), the end-member formula being CaCeFe3+AlMn2+(Si2O7)(SiO4)O(OH). Unit-cell parameters are a = 8.9033(3), b = 5.7066(2), c = 10.1363(3) Å, β = 114.222(2)°, V = 469.66(3) Å3, Z = 2. The crystal structure of ferriakasakaite-(Ce) was refined to a final R1 = 0.0196 for 1960 unique reflections with Fo > 4σ(Fo) and 124 refined parameters.

Waimirite-(Y), orthorhombic YF3, a new mineral from the Pitinga mine, Presidente Figueiredo, Amazonas, Brazil and from Jabal Tawlah, Saudi Arabia: description and crystal structure

2015 ◽  
Vol 79 (3) ◽  
pp. 767-780 ◽  
Author(s):  
Daniel Atencio ◽  
Artur C. Bastos Neto ◽  
Vitor P. Pereira ◽  
José T. M. M. Ferron ◽  
M. Hoshino ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Saudi Arabia ◽  
Single Crystal ◽  
Electron Microprobe ◽  
Empirical Formula ◽  
Unit Cell ◽  
New Mineral ◽  
Charge Balance ◽  
Unit Cell Parameters ◽  
Cell Parameters

AbstractWaimirite-(Y) (IMA 2013-108), orthorhombic YF3, occurs associated with halloysite, in hydrothermal veins (up to 30 mm thick) cross-cutting the albite-enriched facies of the A-type Madeira granite (∼1820 Ma), at the Pitinga mine, Presidente Figueiredo Co., Amazonas State, Brazil. Minerals in the granite are 'K-feldspar', albite, quartz, riebeckite, 'biotite', muscovite, cryolite, zircon, polylithionite, cassiterite, pyrochlore-group minerals, 'columbite', thorite, native lead, hematite, galena, fluorite, xenotime-(Y), gagarinite-(Y), fluocerite-(Ce), genthelvite–helvite, topaz, 'illite', kaolinite and 'chlorite'. The mineral occurs as massive aggregates of platy crystals up to ∼1 μm in size. Forms are not determined, but synthetic YF3 displays pinacoids, prisms and bipyramids. Colour: pale pink. Streak: white. Lustre: non-metallic. Transparent to translucent. Density (calc.) = 5.586 g/cm3 using the empirical formula. Waimirite-(Y) is biaxial, mean n = 1.54–1.56. The chemical composition is (average of 24 wavelength dispersive spectroscopy mode electron microprobe analyses, O calculated for charge balance): F 29.27, Ca 0.83, Y 37.25, La 0.19, Ce 0.30, Pr 0.15, Nd 0.65, Sm 0.74, Gd 1.86, Tb 0.78, Dy 8.06, Ho 1.85, Er 6.38, Tm 1.00, Yb 5.52, Lu 0.65, O (2.05), total (97.53) wt.%. The empirical formula (based on 1 cation) is (Y0.69Dy0.08Er0.06Yb0.05Ca0.03Gd0.02Ho0.02Nd0.01Sm0.01Tb0.01Tm0.01Lu0.01)Σ1.00[F2.54〈0.25O0.21]Σ3.00. Orthorhombic, Pnma, a = 6.386(1), b = 6.877(1), c = 4.401(1) Å, V = 193.28(7) Å3, Z = 4 (powder data). Powder X-ray diffraction (XRD) data [d in Å (I) (hkl)]: 3.707 (26) (011), 3.623 (78) (101), 3.438 (99) (020), 3.205 (100) (111), 2.894 (59) (210), 1.937 (33) (131), 1.916 (24) (301), 1.862 (27) (230). The name is for the Waimiri-Atroari Indian people of Roraima and Amazonas. A second occurrence of waimirite-(Y) is described from the hydrothermally altered quartz-rich microgranite at Jabal Tawlah, Saudi Arabia. Electron microprobe analyses gave the empirical formula (Y0.79Dy0.08Er0.05Gd0.03Ho0.02Tb0.01Tm0.01Yb0.01)Σ1.00[F2.85O0.08〈0.07]Σ3.00. The crystal structure was determined with a single crystal from Saudi Arabia. Unit-cell parameters refined from single-crystal XRD data are a = 6.38270(12), b = 6.86727(12), c = 4.39168(8) Å, V = 192.495(6) Å3, Z = 4. The refinement converged to R1 = 0.0173 and wR2 = 0.0388 for 193 independent reflections. Waimirite-(Y) is isomorphous with synthetic SmF3, HoF3 and YbF3. The Y atom forms a 9-coordinated YF9 tricapped trigonal prism in the crystal structure. The substitution of Y for Dy, as well as for other lanthanoids, causes no notable deviations in the crystallographic values, such as unit-cell parameters and interatomic distances, from those of pure YF3.

scholarly journals Celestine from Valea Sarii (Vrancea region): New Data and Crystal Structure Refinement

2020 ◽  
Vol 71 (8) ◽  
pp. 72-79
Author(s):  
Gheorghe Branoiu ◽  
Aura Cehlarov ◽  
Diana Cursaru ◽  
Sonia Mihai
Keyword(s):  
Crystal Structure ◽  
Optical Microscopy ◽  
Structure Refinement ◽  
Unit Cell ◽  
Crystal Structure Refinement ◽  
Unit Cell Parameters ◽  
Ore Deposit ◽  
Cell Parameters ◽  
Eastern Carpathians ◽  
Vrancea Region

In the paper has been analyzed the crystal structure of a celestine sample from Valea Sarii (Vrancea region, Romania) located in the Eastern Carpathians Foredeep. The celestine sample was also studied by optical microscopy, chemical and thermal analysis. The unit cell parameters of the celestine structure refined in the space group Pnma were: a=8.39769 �, b=5.38415 �, c=6.88167 �, Z=4. The chemical composition of the celestine crystals was determined by EDX analysis. The optical characteristics of the sample were studied by optical microscopy. A new set of the unit cell parameters and fractional coordinates of the celestine crystal structure were determined. Also were determined the bond lengths in the Sr-O12 and SO4 polyhedra. The sample was collected in the massive mineralization area of the Valea Sarii ore deposit, the largest celestine ore deposit in Romania.

Almeidaite, Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2, a new crichtonite-group mineral, from Novo Horizonte, Bahia, Brazil

2015 ◽  
Vol 79 (2) ◽  
pp. 269-283 ◽  
Author(s):  
Luiz A. D. Menezes Filho ◽  
Nikita V. Chukanov ◽  
Ramiza K. Rastsvetaeva ◽  
Sergey M. Aksenov ◽  
Igor V. Pekov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Empirical Formula ◽  
Unit Cell ◽  
Hexagonal Prism ◽  
Unit Cell Parameters ◽  
Group Mineral ◽  
Space Group ◽  
Cell Parameters ◽  
Contact Surfaces ◽  
Planar Contact

AbstractAlmeidaite (IMA 2013-020), ideally Pb(Mn, Y)Zn2(Ti,Fe3+)18O36(O, OH)2, from Novo Horizonte, Bahia, Brazil, occurs in association with quartz, rutile, anatase, hematite, kaolinite, muscovite, xenotime-(Y) and bastnaesite-(La). Almeidaite forms isolated, black, opaque, sub-metallic, platy crystals flattened on [0001], measuring up to 30 mm 6 30 mm 6 6 mm in size, dominated by the basal pinacoid {0001}, which is bounded by various, mostly steep, rhombohedra and the hexagonal prism {1120}. Most of the crystals are multiply twinned, with non-planar contact surfaces that are approximately parallel to the c axis. The streak is brown. Reflectance values are [(Ro, Re) λ (nm)]: (12.78, 15.39) 470; (12.86, 15.43) 546; (12.91, 15.55) 589; (13.04, 15.75) 650. The empirical formula is (Pb0.59Sr0.12Ca0.04La0.03)Σ0.78(Mn0.54Y0.46)Σ1.00Zn1.43(Ti13.02Fe4.983+)Σ18.00(Fe0.323+Mn0.15)Σ0.47[O37.18(OH)0.82]Σ38.00. It is trigonal, space group R3, with the unit-cell parameters a = 10.4359(2), c = 21.0471(4) Å, V = 1985.10(7) Å3 and Z = 3. The crystal structure was solved (R1 = 0.039) using 2110 unique reflections with I > 3σ(I). Almeidaite is a member of the crichtonite group with Pb dominant in the A site (with 12-fold coordination) and Zn dominant in the T site (with 4-fold coordination). It is a Zn analogue of senaite and a Pb analogue of landauite. The mineral is named after Professor Fernando Flávio Marques de Almeida (1916–2013).

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

Pb-Sb zrudnění z Antimonitové žíly, důl Rudolf, Bohutín (Česká republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 275-280
Author(s):  
Pavel Škácha ◽  
Jiří Sejkora
Keyword(s):  
Czech Republic ◽  
Chemical Composition ◽  
Empirical Formula ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ore District ◽  
Archive Material

The Pb-Sb mineralization with dominant stibnite and plagionite and associated semseyite and zinkenite was found in an archive material collected at the Antimonitová vein, Bohutín, Březové Hory ore district (Czech Republic). Plagionite forms subhedral aggregates up to 1 mm in size. The unit-cell parameters of plagionite for monoclinic space group C2/c refined from the X-ray powder data are: a 13.4890(17), b 11.8670(14), c 19.997(2) Å, β 107.199(8)° and V 3057.9(6) Å3. Its chemical composition (average of 26 analyses, based on 30 apfu) corresponds to the empirical formula Pb5.02Sb8.15S16.82. Associated zinkenite is forming subhedral crystals up to 1 mm in size. Its empirical formula can be expressed as (Cu0.25Ag0.02Fe0.01)Σ0.28Pb9.22Sb22.19S41.31 (average of 26 analyses, based on 73 apfu). Semseyite aggregates have the empirical formula (Pb8.72Fe0.14)8.86Sb8.42S20.73 (average of 11 analyses, based on 38 apfu).

Zeolitová mineralizace s gmelinitem-K z Jedlky u Benešova nad Ploučnicí (Česká republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 213-229
Author(s):  
Petr Pauliš ◽  
Libor Hrůzek ◽  
Oldřich Janeček ◽  
Zdeněk Dolníček ◽  
Volker Betz ◽  
...  
Keyword(s):  
Czech Republic ◽  
Empirical Formula ◽  
Unit Cell ◽  
Mineral Species ◽  
Chemical Analyses ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Quantitative Chemical

A new locality of zeolite minerals occurs on the NE edge of the Jedlka village, at the SE slope of the Hlídka hill, 2 km to W of Benešov nad Ploučnicí (northern Bohemia, Czech Republic). The mineralization is developed in Cenozoic analcime-nepheline tephrite. Ten zeolite mineral species (gmelinite-K, analcime, harmotome, chabazite-Ca, lévyne-Ca, mezolite, natrolite, offretite, phillipsite-K, thomsonite-Ca) were found in small amygdule cavities of tephrite. The most interesting is gmelinite-K, a rare zeolite worldwide, which forms clear, white or slightly yellowish, hexagonal lenticular crystals up to 7 mm, always intergrown with the chabazite-Ca. The unit-cell parameters of gmelinite-K, refined from the powder X-ray data, are a = 13.795 (19), c = 9.811(6) Å and V = 1616.8(3) Å3; its quantitative chemical analyses correspond to the empirical formula (K2.32Ca1.86Sr0.53Na0.20Ba0.19)Σ5.10(Al8.14Si16.01O48)·22H2O.

scholarly journals The crystal structure of alstonite, BaCa(CO3)2: an extraordinary example of ‘hidden’ complex twinning in large single crystals

2020 ◽  
Vol 84 (5) ◽  
pp. 699-704
Author(s):  
Luca Bindi ◽  
Andrew C. Roberts ◽  
Cristian Biagioni
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Structure Determination ◽  
Unit Cell ◽  
Crystal Structure Determination ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Structure Determinations

AbstractAlstonite, BaCa(CO3)2, is a mineral described almost two centuries ago. It is widespread in Nature and forms magnificent cm-sized crystals. Notwithstanding, its crystal structure was still unknown. Here, we report the crystal-structure determination of the mineral and discuss it in relationship to other polymorphs of BaCa(CO3)2. Alstonite is trigonal, space group P31m, with unit-cell parameters a = 17.4360(6), c = 6.1295(2) Å, V = 1613.80(9) Å3 and Z = 12. The crystal structure was solved and refined to R1 = 0.0727 on the basis of 4515 reflections with Fo > 4σ(Fo) and 195 refined parameters. Alstonite is formed by the alternation, along c, of Ba-dominant and Ca-dominant layers, separated by CO3 groups parallel to {0001}. The main take-home message is to show that not all structure determinations of minerals/compounds can be solved routinely. Some crystals, even large ones displaying excellent diffraction quality, can be twinned in complex ways, thus making their study a crystallographic challenge.

scholarly journals Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 486 ◽  
Author(s):  
Andrey A. Zolotarev ◽  
Elena S. Zhitova ◽  
Maria G. Krzhizhanovskaya ◽  
Mikhail A. Rassomakhin ◽  
Vladimir V. Shilovskikh ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Coal Basin ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Mineral Phases

The technogenic mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the burned dumps of the Chelyabinsk coal basin have been investigated by single-crystal X-ray diffraction, scanning electron microscopy and high-temperature powder X-ray diffraction. The NH4MgCl3·6H2O phase is monoclinic, space group C2/c, unit cell parameters a = 9.3091(9), b = 9.5353(7), c = 13.2941(12) Å, β = 90.089(8)° and V = 1180.05(18) Å3. The crystal structure of NH4MgCl3·6H2O was refined to R1 = 0.078 (wR2 = 0.185) on the basis of 1678 unique reflections. The (NH4)2Fe3+Cl5·H2O phase is orthorhombic, space group Pnma, unit cell parameters a = 13.725(2), b = 9.9365(16), c = 7.0370(11) Å and V = 959.7(3) Å3. The crystal structure of (NH4)2Fe3+Cl5·H2O was refined to R1 = 0.023 (wR2 = 0.066) on the basis of 2256 unique reflections. NH4MgCl3·6H2O is stable up to 90 °C and then transforms to the less hydrated phase isotypic to β-Rb(MnCl3)(H2O)2 (i.e., NH4MgCl3·2H2O), the latter phase being stable up to 150 °C. (NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. Hydrogen bonds provide an important linkage between the main structural units and play the key role in determining structural stability and physical properties of the studied phases. The mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O are isostructural with natural minerals novograblenovite and kremersite, respectively.

scholarly journals Structural characterization of a novel monotreme-specific protein with antimicrobial activity from the milk of the platypus

2018 ◽  
Vol 74 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Janet Newman ◽  
Julie A. Sharp ◽  
Ashwantha Kumar Enjapoori ◽  
John Bentley ◽  
Kevin R. Nicholas ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antimicrobial Activity ◽  
Mammalian Cells ◽  
Unit Cell ◽  
Protein Crystal ◽  
Unit Cell Parameters ◽  
Flag Epitope ◽  
Data Set ◽  
Space Group ◽  
Cell Parameters

Monotreme lactation protein (MLP) is a recently identified protein with antimicrobial activity. It is present in the milk of monotremes and is unique to this lineage. To characterize MLP and to gain insight into the potential role of this protein in the evolution of lactation, the crystal structure of duck-billed platypus (Ornithorhynchus anatinus) MLP was determined at 1.82 Å resolution. This is the first structure to be reported for this novel, mammalian antibacterial protein. MLP was expressed as a FLAG epitope-tagged protein in mammalian cells and crystallized readily, with at least three space groups being observed (P1,C2 andP21). A 1.82 Å resolution native data set was collected from a crystal in space groupP1, with unit-cell parametersa= 51.2,b= 59.7,c= 63.1 Å, α = 80.15, β = 82.98, γ = 89.27°. The structure was solved by SAD phasing using a protein crystal derivatized with mercury in space groupC2, with unit-cell parametersa= 92.7,b = 73.2,c= 56.5 Å, β = 90.28°. MLP comprises a monomer of 12 helices and two short β-strands, with much of the N-terminus composed of loop regions. The crystal structure of MLP reveals no three-dimensional similarity to any known structures and reveals a heretofore unseen fold, supporting the idea that monotremes may be a rich source for the identification of novel proteins. It is hypothesized that MLP in monotreme milk has evolved to specifically support the unusual lactation strategy of this lineage and may have played a central role in the evolution of these mammals.

Crystal structure of three diaza-crowns-18

1997 ◽  
Vol 212 (5) ◽  
Author(s):  
P. Dokurno ◽  
R. Trokowski ◽  
B. Kościuszko-Panek ◽  
T. Ossowski ◽  
A. Konitz ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Space Groups ◽  
Cell Parameters

AbstractThe crystal structures of three diaza crowns-18, namely 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (crown 1), 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diacetonitrile (crown 2) and N,N′-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyldi-2,1-ethanediyl)bis-[4-methyl-benzenesulfonamide] (crown 3) have the following space groups and unit cell parameters: crown 1(C

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